Architecture desing using national serializer and deserialis

[Jon]

Hello

I need help on using serializer and deserializer in an electornic card.
The serializer and deserializer are from national DS90CR287 and DS90CR288
I'm working with an electronic card that use a serializer of 4 channels
where the input clock is 40Mhz. when the data in the inputs of the
serializer changes in a slow rate the deserializer and FPGA in the other
card can decode the data properly. when the data in the inputs of the
serializer changes in a high rate ( every 50ns ) the data after the
deserializer and the FPGA in the other card can't decode the data.

The thing is that there are some cards the work and some others that
doesn't
work.
When I look for a diference I found that the 3.3v supply to the serializer
is stable where the card works O.K and when the 3.3v supply has noise the
card doesn't work .

This card is a part of a system. the power supply to the system is from a
power card.
When I say that some card works and some don't I meen that I use the same
system but change only the card with the serializer on it.

Hope to get help soon .
Thank you
claudia B.

 

[Swarna Kumar]

I am using ISE 6.1i, I have also installed the 6.1i service pack. <BR>
I am getting the following error when I am trying to synthesize one of my designs. <p>FATAL_ERROR:Xstortability/export/Port_Main.h:127:1.13 - This application has discovered an exceptional condition from which it cannot recover. Process will terminate. To resolve this error, please consult the Answers Database and other online resources at <a href="http://support.xilinx.com">http://support.xilinx.com</a>. If you need further assistance, please open a Webcase by clicking on the "WebCase" link at <a href="http://support.xilinx.com">http://support.xilinx.com</a> <p>What do I do? <p>Swarna

 

[Daniel Lang]

"Jon" &lt;someone@microsoft.com&gt; wrote in message
news:bpaned$n7f$1@news2.netvision.net.il...

Hello

I need help on using serializer and deserializer in an electornic card.
The serializer and deserializer are from national DS90CR287 and DS90CR288
I'm working with an electronic card that use a serializer of 4 channels
where the input clock is 40Mhz. when the data in the inputs of the
serializer changes in a slow rate the deserializer and FPGA in the other
card can decode the data properly. when the data in the inputs of the
serializer changes in a high rate ( every 50ns ) the data after the
deserializer and the FPGA in the other card can't decode the data.

The thing is that there are some cards the work and some others that
doesn't
work.
When I look for a diference I found that the 3.3v supply to the
serializer
is stable where the card works O.K and when the 3.3v supply has noise
the
card doesn't work .

It sounds like the PLL is getting too much noise. The datasheet recommends
a maximum of 100 mV P-P noise on the VCC. You may want to add a LC filter
on the power to the PLL VCC pin and/or run the chip from a low noise linear
regulator (LT1963A or equivalent). Make sure all the VCC pins are bypassed
and keep the noisy digital lines away from the PLL area.

Daniel Lang